Capti must manage network traffic efficiently, especially at the Wide Area Network (WAN) level. One of the key considerations in this setup is the management of MAC (Media Access Control) addresses. This article will explain what a MAC address is, the specific limitations Capti imposes on its FTTB services, and how using a router can help businesses and customers manage these constraints. 

We’ll also highlight a scenario where multiple MAC addresses might be present and how Capti’s WAN setup addresses these challenges.

1. What is a MAC Address in a WAN Context?

A MAC address is a unique identifier assigned to each network interface on a device. It acts like a digital ID, ensuring that data on the network reaches the correct device. In a WAN setup, Capti uses MAC addresses to identify and manage customer devices connected to its network.

When a customer connects their devices to Capti’s FTTB service, the MAC address of each device is logged and managed by the network. This identification helps maintain the integrity of the WAN by controlling the number of devices accessing the service at any given time.

2. MAC Address Limitations in Capti’s FTTB Services

To maintain stability and optimize bandwidth usage across its WAN, Capti implements the following MAC address limitation:

  • Each FTTB service is restricted to a maximum of 4 MAC addresses. This means only up to four devices can connect directly to the service simultaneously.
  • Capti employs MAC address learning with a 5-minute aging timer. If the customer exceeds the maximum MAC count (i.e., if a fifth device tries to connect within the aging window), the WAN will discard traffic from the new device until the timer expires or a device disconnects.

These restrictions are crucial for Capti to ensure the WAN remains reliable, preventing congestion and maintaining the quality of service for all customers using the same FTTB infrastructure.

3. How a Router Solves the MAC Address Limitation for WAN Connectivity

To prevent customers from hitting the MAC address limit and to manage the WAN connection effectively, Capti recommends that customers use a router between their devices and the WAN connection at the User Network Interface (UNI). Here’s how a router helps:
 

  • Single MAC Address Representation: When a router connects to the UNI, it presents only one MAC addressto Capti’s network, regardless of the number of devices connected behind it. This keeps the WAN within the allowed limit of four MAC addresses while allowing customers to connect multiple devices internally.
  • Network Address Translation (NAT): The router manages multiple internal devices using NAT, translating the internal private IP addresses and MAC addresses to a single public MAC address when communicating with the WAN. This way, Capti’s FTTB service only needs to recognize the router’s MAC address, keeping the WAN usage efficient.

By using a router, businesses and customers can connect a wide range of devices—dozens, or even hundreds—without exceeding the 4-MAC address limit imposed on Capti’s FTTB services.